Modular data center

ABSTRACT

Described are methods, systems, and apparatus, including computer program products, relating to an air module and control thereof. An air module can include a controller, an air intake module configured to receive first air from a first air source and to receive second air from a second air source, an evaporative cooling module in fluid communication with the air intake module, and a mechanical cooling module in fluid communication with the evaporative cooling module. The controller can be configured to cause the intake module to mix the first air and the second air to form intake air, and selectively cool the intake air to form supply air by at least one of causing the evaporative cooling module to selectively cool the intake air, and causing the mechanical cooling module to selectively cool the intake.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application claims the benefit of, and priority to U.S. PatentApplication No. 61/750,689, filed on Jan. 9, 2013, and titled, “ModularData Center,” the entire contents of which are incorporated herein byreference. This application is a Continuation-In-Part of U.S. patentapplication Ser. No. 13/839,709, filed on Mar. 15, 2013, and titled,“Modular Data Center,” the entire contents of which are incorporatedherein by reference.

TECHNOLOGICAL FIELD

The present technology relates generally to data centers and, morespecifically, to modular data centers.

BACKGROUND

Generally, data centers are facilities that support the operation of ITequipment. In one aspect, a data center can involve managing theenvironment of the IT equipment (e.g., managing the temperature of theenvironment surrounding the IT equipment) to provide cooling for the ITequipment. Typical approaches to managing the environment of the ITequipment can include the use of conventional HVAC units to mechanicallycool air. Such approaches can rely exclusively on mechanically coolingthe air within the data center, which can lead to excessive power usageand inefficiency.

SUMMARY

Accordingly, there is a need for methods and systems for efficientlymanaging the data center environment. In one aspect, an air module caninclude a controller; an air intake module configured to receive firstair from a first air source and to receive second air from a second airsource; an evaporative cooling module in fluid communication with theair intake module; and a mechanical cooling module in fluidcommunication with the evaporative cooling module. The controller can beconfigured to cause the intake module to mix, based on at least a supplyair temperature set point, the first air and the second air to formintake air, and selectively cool the intake air to form supply air by atleast one of causing the evaporative cooling module to selectively cool,based on at least the supply air temperature set point, the intake air,and causing the mechanical cooling module to selectively cool the intakeair based on at least the supply air temperature set point. In variousembodiments, a controller may execute logic to evaluate conditions anddetermine instructions for assessing and controlling data centeroperating conditions. In various embodiments a data center intelligentcontrol system is a computer-based software system that gathers andanalyzes data, generates instructions and communicates instructions tothe controller.

In another aspect, a computer implemented method for controlling an airmodule can include generating, by a controller, a first instruction tocause an intake module to selectively mix, based upon a supply airtemperature set point, first air and second air to form intake air;generating, by the controller, a second instruction to selectively coolthe intake air to form supply air, wherein the second instructionincludes at least one of instructions to cause an evaporative coolingmodule to selectively cool, based on at least the supply air temperatureset point, the intake air, and instructions to cause a mechanicalcooling module to selectively cool, based on at least the supply airtemperature set point, the intake air.

In another aspect, a modular data center includes an air module. The airmodule can include an air module controller; an air intake moduleconfigured to receive first air from a first air source and to receivesecond air from a second air source; an evaporative cooling module influid communication with the air intake module; and a mechanical coolingmodule in fluid communication with the evaporative cooling module. Theair module controller can be configured to cause the intake module tomix the first air and the second air based on at least a supply airtemperature set point to form intake air, and the controller can beconfigured to form supply air by at least one of causing the evaporativecooling module to cool the intake air selectively based on at least thesupply air temperature set point, and causing the mechanical coolingmodule to cool the intake air selectively based on at least the supplyair temperature set point. The modular data center can include one ormore data center modules and a supply air conduit in fluid communicationwith the air module and a data center module of the one or more datacenter modules to carry supply air from the air module to the one ormore data center modules.

In some embodiments, the first air source is a source of return air. Insome embodiments, the second air source is a source of outside air.

In some embodiments, the controller is further configured to form thesupply air substantially from the first air, if a temperature of thefirst air is less than the supply air temperature set point.

In some embodiments, the controller is further configured to form thesupply air by mixing the first air and the second air, if a firsttemperature of the first air is greater than the supply air temperatureset point, a second temperature of the second air is less than or equalto the supply air temperature set point, and a dew point of the secondair is less than or equal to an upper limit of a dew point range andgreater than or equal to a lower limit of the dew point range.

In some embodiments, the controller is further configured to form mixedair by mixing the first air and the second air, if a first temperatureof the first air is greater than the supply air temperature set point, asecond temperature of the second air is less than the first temperature,a dew point of the second air is less than a lower limit of a dew pointrange, and a wet bulb temperature of the second air is less than orequal to a wet bulb temperature corresponding to the supply airtemperature set point at the lower limit of a dew point range, and formthe supply air by evaporatively cooling the mixed air with theevaporative cooling module.

In some embodiments, the controller is further configured to form supplyair substantially from the second air by evaporatively cooling thesecond air with the evaporative cooling module, if a first temperatureof the first air is greater than the supply air temperature set point, asecond temperature of the second air is greater than the supply airtemperature set point, a dew point of the second air is less than orequal to an upper limit of a dew point range, and a wet bulb temperatureof the second air is within an evaporative cooling wet bulb temperaturerange.

In some embodiments, the controller is further configured to form supplyair substantially from the first air by mechanically cooling the firstair with the mechanical cooling module, if a dew point of the second airis greater than an upper limit of a dew point range, a dew point of thefirst air is less than or equal to an upper limit of a dew point range,and a first temperature of the first air is greater than the supply airtemperature set point. In some embodiments, the controller is furtherconfigured to form supply air substantially from the first air bymechanically cooling the first air with the mechanical cooling module,if a wet bulb temperature of the second air is greater than or equal toan upper limit of an evaporative cooling wet bulb temperature range, adew point of the first air is less than or equal to an upper limit of adew point range, and a first temperature of the first air is greaterthan the supply air temperature set point.

In some embodiments, the controller is further configured to form supplyair substantially from the first air by mechanically cooling the firstair with the mechanical cooling module, if a dew point of the first airis greater than an upper limit of a dew point range, and a dew point ofthe second air is greater than the upper limit of a dew point range. Insome embodiments, the controller is further configured to form supplyair substantially from the first air by mechanically cooling the firstair with the mechanical cooling module, if a dew point of the first airis greater than an upper limit of a dew point range and a wet bulbtemperature of the second air is greater than or equal to an upper limitof an evaporative cooling wet bulb temperature range.

In some embodiments, the controller is further configured to form supplyair substantially from the second air by evaporatively cooling thesecond air with the evaporative cooling module, if a dew point of thefirst air is less than a lower limit of a dew point range, a dew pointof the second air is less than the lower limit of the dew point range, afirst temperature of the first air is greater than the supply airtemperature set point, a second temperature of the second air is greaterthan the first temperature of the first air, and a wet bulb temperatureof the second air is less than a wet bulb temperature corresponding tothe supply air temperature set point at the lower limit of the dew pointrange.

In some embodiments, the controller is further configured to form mixedair by mixing the first air and the second air, if the secondtemperature of the second air is greater than the first temperature ofthe first air, a dew point of the first air is greater than a lowerlimit of a dew point range, and a dew point of the second air is lessthan the lower limit the dew point range; and to form the supply air byevaporatively cooling the mixed air with the evaporative cooling module.

In some embodiments, the first instruction includes instructions to formthe intake air substantially from the first air, if a temperature of thefirst air is less than the supply air temperature set point.

In some embodiments, the first instruction includes instructions to formthe intake air by mixing the first air and the second air, if a firsttemperature of the first air is greater than the supply air temperatureset point, a second temperature of the second air is less than or equalto the supply air temperature set point, and a dew point of the secondair is less than or equal to an upper limit of a dew point range andgreater than or equal to a lower limit of the dew point range.

In some embodiments, the first instruction includes instructions to formintake air by mixing the first air and the second air, wherein thesecond instruction includes instructions to cause the evaporativecooling module to selectively cool, based on at least the supply airtemperature set point, the intake air, if a first temperature of thefirst air is greater than the supply air temperature set point, a secondtemperature of the second air is less than the first temperature, a dewpoint of the second air is less than a lower limit of a dew point range,and a wet bulb temperature of the second air is less than or equal to awet bulb temperature corresponding to the supply air temperature setpoint at the lower limit of a dew point range.

In some embodiments, the first instruction includes instructions tocreate intake air substantially from second air and the secondinstruction includes instructions to cause the evaporative coolingmodule to selectively cool, based on at least the supply air temperatureset point, the intake air, if a first temperature of the first air isgreater than the supply air temperature set point, a second temperatureof the second air is greater than the supply air temperature set point,a dew point of the second air is less than or equal to an upper limit ofa dew point range, and a wet bulb temperature of the second air iswithin an evaporative cooling wet bulb temperature range.

In some embodiments, the first instruction includes instructions tocreate intake air substantially from first air, wherein the secondinstruction includes instructions to cause the mechanical cooling moduleto selectively cool, based on at least the supply air temperature setpoint, the intake air, if a dew point of the second air is greater thanan upper limit of a dew point range, a dew point of the first air isless than or equal to an upper limit of a dew point range, and a firsttemperature of the first air is greater than the supply air temperatureset point. In some embodiments, the first instruction includesinstructions to create intake air substantially from first air, whereinthe second instruction includes instructions to cause the mechanicalcooling module to selectively cool, based on at least the supply airtemperature set point, the intake air, if a wet bulb temperature of thesecond air is greater than or equal to an upper limit of an evaporativecooling wet bulb temperature range, a dew point of the first air is lessthan or equal to an upper limit of a dew point range, and a firsttemperature of the first air is greater than the supply air temperatureset point.

In some embodiments, the first instruction includes instructions tocreate intake air substantially from first air, wherein the secondinstruction includes instructions to cause the mechanical cooling moduleto selectively cool, based on at least the supply air temperature setpoint, the intake air, if a dew point of the first air is greater thanan upper limit of a dew point range and a dew point of the second air isgreater than the upper limit of a dew point range. In some embodiments,the first instruction includes instructions to create intake airsubstantially from first air and the second instruction comprisesinstructions to cause the mechanical cooling module to selectively cool,based on at least the supply air temperature set point, the intake air,if a dew point of the first air is greater than an upper limit of a dewpoint range, and a wet bulb temperature of the second air is greaterthan or equal to an upper limit of an evaporative cooling wet bulbtemperature range.

In some embodiments, the first instruction includes instructions tocreate intake air substantially from second air and the secondinstruction includes instructions to cause the evaporative coolingmodule to selectively cool, based on at least the supply air temperatureset point, the intake air, if a dew point of the first air is less thana lower limit of a dew point range, a dew point of the second air isless than the lower limit of the dew point range, a first temperature ofthe first air is greater than the supply air temperature set point, asecond temperature of the second air is greater than the firsttemperature of the first air, and a wet bulb temperature of the secondair is less than a wet bulb temperature corresponding to the supply airtemperature set point at the lower limit of the dew point range.

In some embodiments, the first instruction includes instructions to formintake air by mixing the first air at a first temperature and the secondair at a second temperature and the second instruction includesinstructions to cause the evaporative cooling module to selectivelycool, based on the at least the supply air temperature set point, theintake air, if the second temperature of the second air is greater thanthe first temperature of the first air, a dew point of the first air isgreater than a lower limit of a dew point range, and a dew point of thesecond air is less than the lower limit the dew point range.

In some embodiments, the modular data center can include a data centermodule controller. In some embodiments, the modular data center caninclude a data center module intake damper configured to control supplyair entering the data center module from the supply air conduit. In someembodiments, the data center module controller is configured to actuatethe data center module intake damper based on at least one of atemperature and humidity of air in the data center module. In someembodiments, the air module further includes a fan array. In someembodiments, the air module controller is further configured to adjustan air flow of the fan array to maintain a substantially constant airpressure in the supply air conduit.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features, and advantages of the presenttechnology, as well as the technology itself, will be more fullyunderstood from the following description of various embodiments, whenread together with the accompanying drawings, in which:

FIG. 1A depicts a top view of a data center;

FIG. 1B depicts a side view of a data center;

FIG. 2 depicts a side view of an air module;

FIG. 3 depicts a side view of a data module;

FIG. 4 depicts a side view of a data module;

FIG. 5 depicts an exemplary air flow through a data module; and

FIG. 6 depicts a top view of data center.

DETAILED DESCRIPTION

Described herein are modular data centers and methods of controlling thesame. In some embodiments, a data center can provide an operatingenvironment for IT equipment, such as servers, storage devices,networking devices, power distribution equipment, uninterruptible powersupplies, etc. For example, a data center can facilitate cooling ITequipment, which can generate heat when operating. In some embodiments,a data center can include an air module and one or more data centermodules (e.g., data modules or other data center modules) housed in abuilding (e.g., in a large open space within the building). Air modulescan intake air from the surrounding environment (“return air”) (e.g.,air from within the building housing the data center). Air modules canintake air from the outdoors (“outside air”) (e.g., via a duct connectedto the exterior of the building housing the data center). Air modulescan condition return air, outside air, and/or a mixture thereof toprovide to the data modules. Air modules can be connected to datamodules via ducts, pipes, or other conduits to provide conditioned air(“supply air”) to the data modules. Within the data modules, heat energycan be transferred from IT equipment to air. Air within the data modulescan be exhausted from the data modules via vents, ducts, pipes, or otherconduits. Air within the data modules can be exhausted from the datamodules via vents, ducts, pipes, or other conduits connected to one ormore air modules. Air can be exhausted from the data modules into thesurrounding environment (e.g., into the building housing the datacenter). In some embodiments, the supply air from the air modules can beat a lower temperature than the air within the data modules. When thesupply air enters the data module, it can be used to cool IT equipment.As a result of cooling IT equipment within the data module, return aircan be at an elevated temperature. In some embodiments, air modules cancool and/or heat the return air before providing it to the data modulesas supply air.

As will be described in greater detail below, an air module can usedifferent techniques to provide supply air at a desired temperatureand/or humidity. For example, the air module can selectively mix returnair with outside air to form intake air and/or supply air. The airmodule can selectively utilize evaporative cooling (e.g., direct orindirect evaporative cooling) to cool intake air and/or change itshumidity. The air module can utilize a fluid-based heat exchanger (e.g.,mechanical cooling or a cooling coil) to cool intake air. The air modulecan utilize a dehumidifier to reduce the humidity of intake air. The airmodule can utilize a heater to heat intake air. In some embodiments,selective use of these different techniques can increase the efficiencyof the air module providing supply air (e.g., by using less power toprovide supply air to the data modules at a desired temperature and/orhumidity).

FIG. 1A depicts a top view of data center 100. Data center 100 includesair modules 105 a-105 d (generally air modules 105). Air modules 105 areconnected to data modules 110 a-110 d via supply air conduit 115. Supplyair conduit 115 can be pipes, ducts, or any other conduit for carryingair between air modules 105 and data modules 110.

FIG. 1B depicts a side view of data center 100. As illustrated, airmodule 105 d connects to supply air conduit 115. Supply air conduit 115connects to sub-floor space 120 a of data module 110 a. Sub-floor space120 a of data module 110 a connects to sub-floor space 120 b of datamodule 110 b. Sub-floor space 120 b of data module 110 b connects tosub-floor space 120 c of data module 110 c. Sub-floor space 120 c ofdata module 110 c connects to sub-floor space 120 d of data module 110d. In the illustrated configuration, sides 125, 130, and 135 ofsub-floor spaces 120 are closed, forming a plenum consisting ofsub-floor space 120 a-120 d.

Air modules 105 can provide supply air to data modules 110 via supplyconduit 115. In some embodiments, air modules 105 pressurize the supplyair in supply air conduit 115 and sub-floor spaces 120, creating apressure differential between the air pressure in the supply air conduit115/sub-floor spaces 120 and the surrounding environment. The pressuredifferential can cause air (e.g., supply air) to flow from air modules105 to data modules 110, air to flow through data modules 110, and airto flow from data modules 110 to the surrounding environment.

Data center 100 is an exemplary data center utilizing the disclosedtechnology. Other configurations are contemplated. For example, thenumber of air modules and data modules can be increased or decreaseddepending on the amount of cooling required by IT equipment. As anotherexample, air modules and data modules can be placed outdoors.

FIG. 2 depicts a side view of air module 105 d. It should be appreciatedthat air modules 105 a-105 c can have similar configurations andfunctionality as air module 105 d. Air module 105 d includes air intakemodule 205, filtration module 210, evaporative cooling module 215, DXcooling module 220, and fan array 225. Return air can enter the airmodule 105 d through return air intake damper 247, and outside air canenter the air module 105 d through outside intake damper 250. Air module105 d includes controller 227. Controller 227 can control the operationof air module 105 d, as will be described in greater detail below.

In various embodiments, controller 227 may execute logic to evaluateconditions and determine instructions for assessing and controlling datacenter operating conditions. In various embodiments, a data centerintelligent control system (a “DCICS”) is a computer-based softwaresystem that gathers and analyzes data, generates instructions andcommunicates instructions to the controller. The DCICS optimizes datacenters and data center operations by, for example: collecting,monitoring, analyzing, warehousing and mining data; analyzing andpredicting using proprietary algorithms, forecasts, simulations, andmodels to develop alternative data center configurations and processes;optimizing by analyzing a plurality of optimization dimensions anddeveloping and evaluating alternative optimization actions; andgenerating and implementing optimization instructions.

Various embodiments of this disclosure include the DCICS monitoring,analyzing and controlling data centers and related hardware andsoftware, for example, by exchanging data with a controller (e.g.controller 227) and/or sending control instructions to a controller. Invarious embodiments, a DCICS determines, based upon a first expression,a first operation and data collection points associated with data centerassets. Data collection points may include sensors, indicators,detectors, application programming interfaces, system data, etc. Invarious embodiments, the expression may be obtained from a data base, auser interface, another system, a hardware device, etc. DCICS interpretsand/or analyzes the expression and generates machine code instructions,executes the machine code instructions to produce a result of the firstoperation. examines or analyzes the result and determines a controlinstruction, and at least one of executes the control instruction,partially executes the control instruction, and/or communicates thecontrol instruction to a controller, a hardware device or softwareprogram for execution. More information regarding, DCICS and relatedsoftware applications, can be found in U.S. patent application Ser. No.13/788,834 filed on Mar. 7, 2013 and entitled “DATA CENTER INTELLIGENTCONTROL AND OPTIMIZATION,” the contents of which are hereby incorporatedby reference it its entirety.

In some embodiments, one or more of air modules 105 can be in operatingmode, and one or more of air modules 105 can be in a standby mode. Thecontrollers in each air module (e.g., controller 227 in air module 105d) can negotiate to determine the operating/standby state of each airmodule. Air modules 105 that are in standby mode can be switched tooperating mode by their controllers. In some embodiments where one ormore of air modules 105 are in standby mode, the operating/standby modeof each air module 105 can be rotated on a periodic basis (e.g.,monthly) to exercise and equalize runtime of air modules 105. In theevent that one of air modules 105 fails, another one of air modules 105can be changed from standby to operating mode.

In some embodiments, if one or more of air modules 105 in operating modefail, the remaining air modules 105 in operating mode can increaseconditioned air output to compensate for the one or more of air modules105 that fail.

Fan Array Operation

Fan array 225 can include blowers 230. Blowers 230 can be arranged in amatrix (e.g., a 3×3 matrix of blowers). The speed of blowers 230 (e.g.,how fast the fan blade in each blower rotates) can be controlled byvariable frequency drive (VFD) 233. Controller 227 can send a signal toVFD 233 to increase or decrease the speed at which blowers 230 operate.Each of blowers 230 can include backdraft dampers 235. In someembodiments, a VFD can be included for each blower.

In some embodiments, controller 227 can cause VFD 233 for fan array 225to start blowers 230. Controller 227 can open discharge/supply damper237 when the blowers 230 are running. Controller 227 can monitor theopen/closed position of discharge/supply damper 237. Controller 227 canreport a discharge damper alarm condition if discharge/supply damper 237fails to open or close when instructed to by controller 227.

In some embodiments, each blower 230 includes a piezometer ring sensorand CFM transducer (collectively CFM sensor) for measuring air flowthrough each blower 230. Controller 227 can monitor the airflow rate(e.g., in CFM) of each blower 230 using the CFM sensor. Controller 227can adjust the speed of blowers 230 using VFD 233 to maintain a desiredtotal airflow rate at the discharge/supply duct 240 of air module 105 d.In some embodiments, all of blowers 230 can operate at the same speed.In some embodiments, some of blowers 230 can operate at different speedsthan others of blowers 230.

As illustrated, data center 100 of FIG. 1A can include static pressuresensors 140 in supply air conduit 115 to measure static air pressure atthe location of static pressure sensors 140. Controller 227 can monitorstatic pressure in supply air conduit 115 via static pressure sensors140. In some embodiments, static pressure sensors 140 can be used forredundancy. In the event that one of static pressure sensors 140 reportsa static pressure significantly different than the other static pressuresensors 140, controller 227 can report a failed sensor alarm anddisregard the output of the failed static pressure sensor 140.

In some embodiments, Controller 227 can set an airflow setpoint for fanarray 225, causing blowers 230 to maintain airflow at or about theairflow setpoint, in order to maintain a desired static pressure insupply air conduit 115 (e.g., the pressure setpoint can be 0.5 to 1.5IWG).

As illustrated, data center 100 of FIG. 1B can include closing platestatic pressure sensor 145. Closing plate static pressure sensor 145 canbe placed in the sub-floor space of the data module furthest from theair module (e.g., subfloor space 120 d of data module 110 d). Controller227 can monitor the static pressure in subfloor space 120 d via closingplate static pressure sensor 145. Controller 227 can send an alarm ifthe static pressure at the location of the closing plate static pressuresensor 144 falls below a predetermined static pressure (e.g., 0.5 IWG).

In some embodiments, if the static pressure measured by supply staticpressure sensor 243 in discharge/supply duct 240 exceeds a predeterminedstatic pressure setpoint (e.g., 3.0 IWG), relief damper 245 (e.g., anadjustable barometric relief damper) can open to relieve excess supplyair into the surrounding environment to protect air module 105 d, supplyair conduit 115, and other aspects of data center 100.

In some embodiments, upon detecting a loss of airflow at any of blowers230 via the CFM sensor, controller 227 can report a blower failurealarm. Backdraft damper 235 on failed blower 230 can automatically closeto prevent reverse airflow through failed blower 230. Controller 227 cansignal VFD 233 to increase the speed of the remaining operating blowers230 to maintain the required total CFM discharged by fan array 225.

In some embodiments, controller 227 can monitor the status of VFD 233and the amperage draw of fan array 225 via the VFD 233. Upon detecting afailure of VFD 233, controller 227 can report a VFD failure alarm,switch VFD 233 into bypass mode, and energize a sufficient number ofblowers 230 at full speed to maintain the required total CFM dischargedby fan array 225.

In some embodiments, if fan array 225 cannot deliver a predeterminedminimum airflow rate, air module 105 d can be considered “failed.”Controller 227 can report an airflow failure alarm, deenergize airmodule 105 d (e.g., shut down air intake module 205, filtration module210, evaporative cooling module 215, DX cooling module 220, and fanarray 225), close discharge/supply damper 237, close return air intakedampers 247, close outside air intake damper 250, and/or change one ofair modules 105 that is in standby mode to operating mode.

In some embodiments, upon detecting smoke in discharge/supply duct 240via smoke detector 253, smoke detector 253 can report the presence ofsmoke (e.g. an alarm can be reported to a building fire alarm system).Controller 227 can report a smoke detection warning, close outside airintake damper 250, and open return air intake dampers 247 to determinewhether the smoke is coming from the outside air. If after apre-determined amount of time (e.g., 30 seconds), smoke detector 253continues to detect smoke, controller 227 can report a smoke shutdownalarm, deenergize air module 105 d, close discharge/supply damper 237,close return air intake dampers 247, close outside air intake damper250, and/or change one of air modules 105 that is in standby mode tooperating mode.

Mechanical Refrigeration

As described above, air module 105 d can include DX cooling module 220.In some embodiments, DX cooling modules can be fluid based (e.g.,coolant, etc.). In some embodiments, any mechanical refrigeration can beused (e.g., chilled water-based mechanical refrigeration). Asillustrated in FIG. 2, DX cooling module 220 includes coil bank 255 aand coil bank 255 b. Each coil bank 255 can include two coil circuits. Afirst condenser (not shown) can supply coil bank 255 a with coolant(e.g., provide mechanical refrigeration for coil bank 155 a) and asecond condenser (not shown) can supply coil bank 255 b with coolant(e.g., provide mechanical refrigeration for coil bank 155 b).

Upon determining a need for mechanical refrigeration, as describedbelow, controller 227 can enable the first and second condensing units(e.g., in sequence or approximately simultaneously).

Controller 227 can monitor conditions at each condensing unit via acommunication interface (e.g., MODBUS). For example, controller 227 canmonitor the following conditions at each condensing unit: Saturatedsuction temperature (SST) for each coil circuit, discharge pressure foreach coil circuit, suction pressure for each coil circuit, compressoron-off status, and condensing unit alarm state. In some embodiments, ifa condensing unit is in an alarm state, controller 227 can report acondensing unit failure.

Controller 227 can set a leaving air temperature set point for each ofcoil banks 255. In some embodiments, the leaving air temperature setpoint can be determined as described below. In some embodiments, anintegral microprocessor controller in each condensing unit can cycle therefrigerant liquid line solenoid valves, and sequence the operation ofthe compressors and condenser fans, to maintain leaving air at theleaving air temperature set point.

In some embodiments, upon the SST of the refrigerant in a coil bank 255exceeding a predetermined maximum allowable SST (e.g., 54° F.) for morethan a predetermined amount of time (e.g., 10 minutes), controller 227can gradually lower the leaving air temperature set point until the SSTis at or below the maximum allowable SST.

In some embodiments, air module 105 d includes cooling coil bypass 257.Cooling coil bypass 257 can be a duct, pipe, or other conduit. In theillustrated embodiment, cooling coil bypass 257 permits air to bypasscoil banks 255 (e.g., not pass through and/or be cooled by coil banks255). Air module 105 d can include actuated bypass damper 260. In someembodiments, controller 227 can control the opening and closing ofactuated bypass damper 260. Air module 105 d can include bypass damper263.

In some embodiments, controller 227 can control actuated bypass damper260 to mix non-refrigerated air (e.g., air that does not pass throughcoil banks 255) with refrigerated air (e.g., air that passes throughcoil banks 255) to maintain a supply air temperature in discharge/supplyduct 240 at a predetermined supply air temperature (e.g., 75° F.).Supply temperature and humidity sensor 267 can measure the temperatureof supply air in discharge/supply air duct 240. Controller 227 canmonitor the position (e.g., amount open) of actuated bypass damper 260and can report a damper failure alarm if the position of actuated bypassdamper 260 deviates from the position instructed by controller 227.

In some embodiments, actuated bypass damper 260 is not opened beyond apoint where a differential static pressure across cooling coil banks 255falls below a predetermined pressure (e.g., 0.30 IWG), which cancorrespond to a face velocity across coil banks 255.

If actuated bypass damper 260 is open to the coil face velocity limit(e.g., differential static pressure across cooling coil banks 255 is atthe limit above), and the air temperature in discharge/supply duct 240falls below the predetermined supply air temperature (e.g., 75° F.),controller 227 can activate return air duct heater 265. In someembodiments, return air duct heater 265 can include 5 heating cycles,with each heating cycle providing increased heating. Controller 227 canmodulate the first stage of return air duct heater 265, and can cyclestages 2 thru 5, in sequence, as required to maintain the supply airtemperature at the predetermined supply air temperature (e.g., 75° F.).In some embodiments, if return air duct heater 265 fails to operate(e.g., as sensed by a current transformer on the power leads of returnair duct heater 265), controller 227 can report an electric heaterfailure alarm.

In some embodiments, if controller 227 senses via supply temperature andhumidity sensor 267 in discharge/supply duct 240 a supply air dry-bulbtemperature in excess of a predetermined maximum temperature (e.g., 78°F.) for more than a predetermined amount of time (e.g., 15 minutes),indicating a cooling system failure, controller 227 can report a highsupply air temperature alarm, deenergize air module 105 d, closedischarge/supply damper 237, close return air intake dampers 247, closeoutside air intake damper 250, and/or change one of air modules 105 thatis in standby mode to operating mode.

In some embodiments, if controller 227 senses via supply temperature andhumidity sensor 267 in discharge/supply duct 240 a supply air dry-bulbtemperature below a predetermined minimum temperature (e.g., 68° F.) formore than a predetermined amount of time (e.g., 15 minutes), indicatinga failure of the module to limit the amount of cooling, controller 227can report a low supply air temperature alarm, deenergize air module 105d, close discharge/supply damper 237, close return air intake dampers247, close outside air intake damper 250, and/or change one of airmodules 105 that is in standby mode to operating mode.

Controller 227 can compute the supply air dew point temperature (or “dewpoint”) in discharge/supply duct 240. For example, controller 227 canuse the atmospheric pressure at the location of data center 100 and thesupply air dry-bulb temperature and relative humidity, as determined bysupply temperature and humidity sensor 267. If a supply air dew pointtemperature is below a predetermined minimum dew point temperature(e.g., 35° F. DP), indicating a humidification failure, controller 227can report a low supply air dew point temperature alarm, deenergize airmodule 105 d, close discharge/supply damper 237, close return air intakedampers 247, close outside air intake damper 250, and/or change one ofair modules 105 that is in standby mode to operating mode.

If a supply air dew point temperature is above a predetermined maximumdew point temperature (e.g., 62° F. DP), indicating an evaporativecooler control failure, controller 227 can report a high supply air dewpoint temperature alarm, deenergize air module 105 d, closedischarge/supply damper 237, close return air intake dampers 247, closeoutside air intake damper 250, and/or change one of air modules 105 thatis in standby mode to operating mode.

Evaporative Cooling/Humidification Module

Evaporative cooling module 215 can include multiple (e.g., 5)evaporative cooling stages. In some embodiments, the greater number ofstages enabled can result in greater evaporative cooling of air.Controller 227 can enable and disable evaporative cooling module 215. Insome embodiments, controller 227 can control the number of enabled oractive stages of evaporative cooling module 215. An integral controllerwithin evaporative cooling module 215 can start the recirculation pump,energize the UV water sterilization system, control the make-up watersolenoid valve, cycle the drain valve (based on conductivity), and openthe required quantity of staging manifold valves to enable evaporativecooling stages.

Controller 227 can monitor the evaporative cooling module 215 via acommunication interface (e.g., MODBUS). For example, controller 227 canmonitor: open-closed position of each manifold valve, high reservoirlevel alarm, pump on-off status, and water conductivity. Upon sensinghigh reservoir level, pump failure, or excessive water conductivity,controller 227 can send a high reservoir level alarm or a pump failurealarm.

In some embodiments, controller 227 can sense via leak detector 277 forwater on the floor of air module 105 d and can send a water-on-flooralarm.

Modes of Operation

Air modules 105 can operate in different modes based on variousenvironmental conditions. In some embodiments, air modules 105 canoperate with greater efficiency by operating in different modes. Asdescribed in greater detail below, return air and outside air can beselectively mixed to form intake air and/or supply air. Evaporativeand/or mechanical cooling can be applied to intake air to form supplyair.

In some embodiments, as discussed below, the controller 227 can applyone or more tests or logic functions to select the appropriate mode formixing and cooling intake air to form supply air based on one or moreparameters, including return air temperature (Tradb) (e.g., air that airmodule 105 d intakes through return air intake dampers 247), outside airtemperature (Tosadb) (e.g., air that air module 105 d intakes throughreturn air intake dampers 250), dew point temperature of the outside air(Tosadp), and dew point temperature of the return air (Tradp). Thereturn air temperature (Tradb) and dew point temperature of the returnair (Tradp) may be measured or calculated in any suitable manner,including by return air temperature and humidity sensor 270 (FIG. 2).Similarly, the outside air temperature (Tosadb) and dew pointtemperature of the outside air (Tosadp) may be measured or calculated inany suitable manner, including by a temperature and humidity sensor atthe outside air intake damper 250 and/or intake temperature and humiditysensor 275. Additional parameters, described below, used for selectingthe mode of operation can be measured with sensors or calculated by thecontroller 227 using thermodynamic functions, curves, and limits.

In some embodiments, controller 227 can estimate the temperature riseacross fan array 225 (e.g., the amount fan array 225 increases thetemperature of air flowing through it) based on a total fan motor powerof blowers 230 and an air density ratio at the location of data center100 as follows:

TRfdb=Temperature Rise Across Fan Array

TRfdb=Kwfanarray×3413/(1.08×ADR×CFMfanarray)

Where:

Kwfanarray=Measured Total Fan Motor Power of blowers 230 in KW

ADR=Air Density Ratio at the Site Altitude

ADR=Paltitude/14.696

Paltitude=Standard Atmospheric Pressure at Site Altitude

Paltitude=14.696 (−16.8754×10−6Z) 5.2559

Z=Site Altitude in Feet Above Sea Level

CFMfanarray=Summation of the Measured Airflow from each Operating motorof blowers 230 in fan array 225

In some embodiments, controller 227 can maintain the temperature of theair entering fan array 225 at the predetermined supply air temperature(e.g., 75° F.) minus the fan array temperature rise as follows:

Tefdb=Dry Bulb Temperature of Air Entering fan array 230

Tefdb=Module Supply Air Temperature−TRfdb, or

Tefdb=75° F.−TRfdb

Low Return Air Temperature Recirculation Mode

In some embodiments, when the return air temperature (Tradb) is lessthan, or equal to, Tefdb, controller 227 can fully open return airintake dampers 247 and fully close outside air intake damper 250.Controller 227 can modulate the first stage of return air duct heater265, and/or can cycle stages 2 thru 5, in sequence, to maintain anaverage air temperature equal to Tefdb downstream of air filters 273. Ifreturn air duct heater 265 fails to operate (e.g., as sensed by acurrent transformer on the power leads of return air duct heater 265power leads), controller 227 can report an electric heater failurealarm. Controller 227 can disable evaporative cooler module 215 andclose the solenoid valves in evaporative cooling module 215.

Airside Economizer without Humidification or Evaporative Cooling

In some embodiments, when the return air temperature (Tradb) is greaterthan Tefdb, the outside air temperature (Tosadb) is less than or equalto Tefdb, the dew point temperature of the outside air (Tosadp) does notexceed a predetermined high dew point setpoint (DP_UL) (e.g., 59° F.),and the dew point temperature of the outside air (Tosadp) is not lessthan a predetermined low dew point setpoint (DP_LL) (e.g., 41.9° F.),controller 227 can mix outside air with return air to achieve a mixedair temperature equal to Tefdb as sensed by intake air temperature andhumidity sensor 275. If necessary, controller 227 can enable the DXcooling module 220. Controller 227 can disable evaporative coolingmodule 215 and close the solenoid valves in evaporative cooling module215. Controller 227 can disable return air duct heater 265.

Airside Economizer with Humidification

In some embodiments, when the return air temperature (Tradb) is greaterthan Tefdb, the temperature of the outside air (Tosadb) is less than orequal to the return air temperature (Tradb), the dew point temperatureof the outside air is less than a predetermined low dew point setpoint(DP_LL) (e.g., 41.9° F.), and the wet bulb temperature of the outsideair (Tosawb) is less than or equal to Tllwb, controller 227 can mixoutside air with return air to achieve a lower limit mixed air enthalpyentering evaporative cooling module 215 corresponding to Tefdb at a dewpoint temperature of the predetermined low dew point setpoint (e.g.,41.9° F.), as sensed by intake air temperature and humidity sensor 275.

Where:

Tllwb=Lower Limit of Outside Air Wet Bulb Temperature for EvaporativeCooling, Psychrometrically Calculated at Tefdb with a predetermined lowdew point setpoint (e.g., 41.9° F.)

Controller 227 can provide humidification as follows:

a) Controller 227 can predict wet bulb temperature of the mixed airentering evaporative cooling module 215 using the following formulas:

Tmadb=Desired Mixed Air Dry Bulb Temperature Entering the evaporativecooling module 215

Tmadb=Tosadb+((Tradb−Tosadb)(hll−hosa)/(hra−hosa))

Wma=Wosa+((Wra41.9−Wosa)×(Tmadb−Tosadb)/(Tradb−Tosadb))

Tmawb=Psychrometrically Calculated Wet Bulb Temperature of the MixedAir, at Tmadb and Wma

Where:

Tosadb=Outside Air Dry Bulb Temperature

Tosawb=Outside Air Wet Bulb Temperature

Tradb=Return Air Dry Bulb Temperature

RHosa=Outside Air Relative Humidity

RHra=Return Air Relative Humidity

hosa=Psychrometrically Calculated Enthalpy of the Outside Air, at Tosadband RHosa

hll=Psychrometrically Calculated Lower Limit Enthalpy of Mixed Air Airat Tefdb and 41.9° F. Dew point Temperature

hra=Psychrometrically Calculated Enthalpy of the Return Air at Tradb andRHra

Wma=Predicted Humidity Ratio of the Mixed Air Entering the evaporativecooling module 215

Wosa=Psychrometrically Calculated Humidity Ratio of the Outside Air, atTosadb and RHosa

Wra41.9=Psychrometrically Calculated Humidity Ratio of the Return Air,at Tradb and, e.g., 41.9° F. Dew point Temperature

b) Controller 227 can predict temperature possible through an activestage of evaporative cooling, assuming 80% efficiency, using thefollowing formula:

Tevapdb=Tmadb−(0.80×(Tmadb−Tmawb))

Where:

Tevapdb=Predicted Dry Bulb Temperature Leaving an Active EvaporativeCooler Stage

c) Controller 227 can predict the number of active evaporative coolingstages required, assuming a total of 5 stages of evaporative cooling, toachieve a leaving air dry bulb temperature equal to Tefdb using thefollowing formula:

Evapfracdb=Calculated Fraction of Airflow Through evaporative coolingmodule 215 to Maintain Tefdb ° F.

Evapfracdb=(Tmadb−Tefdb)/(Tmadb−Tevapdb)

Stagesdb=Quantity of Evaporative Cooler Stages Required Based on DryBulb Temperature

Stagesdb=(Evapfracdb×5) Rounded Up to Nearest Whole Number, But CannotExceed 5

Controller 227 can determine the required number of evaporative coolerstages to use by the following formula:

Stages=Calculated Number of Evaporative Cooler Valves to Open (Stages ofEvaporative Cooler to Energize)

Stages=Stagesdb, but not less than 0

e) Controller 227 can enable evaporative cooling module 215 and engagethe quantity of evaporative cooler stages calculated above.

f) Controller 227 can mix outside air with return air to achieve a mixedair temperature equal to Tefdb as sensed by intake air temperature andhumidity sensor 275.

g) Controller 227 can enable the DX cooling module 220, if necessary.

Airside Economizer with Supplemental Evaporative Cooling

In some embodiments, when the return air temperature (Tradb) is greaterthan Tefdb, the temperature of the outside air (Tosadb) is greater thanTefdb, the wet bulb temperature of the outside air (Tosawb) is less thanTulwb, the dew point temperature of the outside air (Tosadp) does notexceed a predetermined high dew point setpoint (DP_UL) (e.g., 59° F.),and the wet bulb temperature of the outside air (Tosawb) is greater thanTllwb, controller 227 can fully open outside air intake damper 250 andfully close return air intake dampers 247.

Where:

Tulwb=Upper Limit of Outside Air Wet Bulb Temperature for EvaporativeCooling, Psychrometrically Calculated at Tradb with a predetermined highdew point setpoint (e.g., 59° F.)

dew point a) Controller 227 can predict the temperature possible throughan active stage of the evaporative cooling module 215, assuming 80%efficiency, using the following formula:

Tevapdb=Tosadb−(0.80×(Tosadb−Tosawb))

Where:

Tevapdb=Predicted Dry Bulb Temperature Leaving an Active EvaporativeCooler Stage

Tosadb=Outside Air Dry Bulb Temperature Entering the evaporative coolingmodule 215

Tosawb=Outside Air Wet Bulb Temperature Entering the evaporative coolingmodule 215

b) Controller 227 shall predict the number of active evaporative coolingstages required, assuming a total of 5 stages of evaporative cooling, toachieve a leaving air dry bulb temperature equal to Tefdb using thefollowing formula:

Evapfracdb=Calculated Fraction of Airflow Through evaporative coolingmodule 215 to Maintain Tefdb ° F.

Evapfracdb=(Tosadb−Tefdb)/(Tosadb−Tevapdb)

Stagesdb=Quantity of Evaporative Cooler Stages Required Based on DryBulb Temperature

Stagesdb=(Evapfracdb×5) Rounded Down to Nearest Whole Number, But CannotExceed 5

c) Controller 227 can predict the number of active evaporative coolingstages required, assuming 5 stages of evaporative cooling, to limit themixed air leaving air dew point temperature to a predetermined high dewpoint setpoint (e.g., 59° F.), using the following formula:

Evapfracw=Calculated Fraction of Airflow Through evaporative coolingmodule 215 to Limit Mixed Air Dew point Temperature to a predeterminedhigh dew point setpoint (e.g., 59° F.)

Evapfracw=(Wosa−W59)/(Wosa−Wevap)

Where:

Wevap=Psychrometrically Calculated Humidity Ratio of the Air Leaving theActive Evaporative Cooler Stages, at Tevapdb and Tosawb

Wosa=Psychrometrically Calculated Humidity Ratio of the Air Leaving theInactive Evaporative Cooler Stages, at Tosadb and Tosawb

W59=Psychrometrically Calculated Humidity Ratio at a predetermined highdew point setpoint (e.g., 59° F.)

Stagesw=Quantity of Evaporative Cooler Stages Required Based on HumidityRatio

Stagesw=(Evapfracw×5) Rounded to Nearest Whole Number, But Cannot Exceed5

d) Controller 227 can determine the appropriate number of evaporativecooling stages to use by the following formula:

Stages=Calculated Number of Evaporative Cooler Valves to Open (Stages ofEvaporative Cooler to Energize)

Stages=Lessor of Stagesdb and Stagesw, but not less than 0

e) Controller 227 can predict the mixed air dry bulb temperature leavingthe evaporative cooling module 215 when evaporatively cooled air passingthough the active evaporative cooling stages is mixed with outside airpassing through the inactive stages using the following formula:

Tmixdb=(Tevapdb×Stages/5)+(Tosadb×(5−Stages)/5)

f) Controller 227 can predict the mixed air humidity ratio leavingevaporative cooling module 215 when evaporatively cooled air passingthough the active stages is mixed with untreated outside air passingthrough the inactive stages using the following formula:

Wmix=(Wevap×Stages/5)+(Wosa×(5−Stages)/5)

g) Controller 227 can enable the evaporative cooler module and open thequantity of evaporative cooler stage valves calculated above.

h) Controller 227 can enable the DX cooling module 220, if necessary.

High Ambient Dew Point or Wet Bulb, Sensible Refrigerated Cooling Mode

In some embodiments, if the dew point temperature of the outside air(Tosadp) is greater than a predetermined high dew point setpoint (DP_UL)(e.g., 59° F.) or if the wetbulb temperature of the outside air (Tosawb)is greater than or equal to Tulwb; and additionally, the dew pointtemperature of the return air (Tradp) is less than, or equal to, thepredetermined high dew point setpoint (DP_UL) (e.g., 59° F.) and thereturn air temperature (Tradb) is greater than Tefdb, controller 227 canfully open return air intake dampers 247 and fully close outside airintake damper 250. Controller 227 can enable Mechanical Refrigeration asdescribed above. Controller 227 can disable evaporative cooling module215 and close the solenoid valves on all of the evaporative coolerstages.

High Ambient Dew Point, Dehumidification Mode

In some embodiments, if the dew point temperature of the outside air(Tosadp) is greater than a predetermined high dew point setpoint (DP_UL)(e.g., 59° F.) or the wetbulb temperature of the outside air (Tosawb) isgreater than or equal to Tulwb; and additionally the dew pointtemperature of the return air (Tradp) is greater than the predeterminedhigh dew point setpoint (DP_UL) (e.g., 59° F.), controller 227 can fullyopen return air intake dampers 247 and fully close outside air intakedamper 250.

a) Controller 227 can enable the first condensing unit, if not alreadyenabled, and can reset the leaving air temperature of coil bank 255 a tomaintain a leaving coil temperature of a predetermined temperature(e.g., 58° F.).

b) Controller 227 can control the second condensing unit, coil bank 255b, actuated bypass damper 260, and return air duct heater 265 asdescribed above to maintain the supply air temperature at apredetermined supply air temperature (e.g., 75° F.).

c) Controller 227 can disable the evaporative cooling module 215, if notalready disabled.

Airside Dry Return Air Recirculation with Humidification Mode

In some embodiments, if the dew point temperature of the outside air(Tosadp) is less than the predetermined low dew point setpoint (DP_LL)(e.g., 41.9° F.), the dew point temperature of the return air (Tradp) isless than the predetermined low dew point setpoint (DP_LL) (e.g., 41.9°F.), the temperature of the outside air (Tosadb) is greater than thereturn air temperature (Tradb), the return air temperature (Tradb) isgreater than Tefdb, and the wet bulb temperature of the outside air(Tosawb) is less than Tllwb, controller 227 can enable one stage of theevaporative cooler module 215. Controller 227 can fully close outsideair intake damper 250 and fully open return air intake dampers 247.

Evaporative Cooling with Dry Air Warmer than Return Air Mode

In some embodiments, if the temperature of the outside air (Tosadb) isgreater than the return air temperature (Tradb), the dew pointtemperature of the return air (Tradp) is greater than or equal to thepredetermined low dew point setpoint (DP_LL) (e.g., 41.9° F.), and dewpoint temperature of the outside air (Tosadp) is less than thepredetermined low dew point setpoint (DP_LL) (e.g., 41.9° F.),controller 227 can mix outside air with return air to achieve a mixedair temperature equal to Tefdb as sensed by intake air temperature andhumidity sensor 275. Controller 227 can enable the evaporative coolermodule 215 and open the quantity of evaporative cooler stage valvescalculated above. Controller 227 can enable the DX cooling module 220,if necessary

In some embodiments, controller 227 can control gravity relief hoods(not shown) in the building housing data center 100. Controller 227 canmodulate the dampers in the gravity relief hoods in conjunction withoutside air intake damper 250 to manage the air pressure within thebuilding housing data center 100. For example, the gravity relief hoodscan be closed when outside air intake damper 250 is closed. The gravityrelief hoods can be open when outside air intake damper 250 is open.Controller 227 can monitor the position of each damper in the gravityrelief hoods and report a damper failure alarm for any damper positionthat deviates the position instructed by controller 227.

Air Filters

Controller 227 can monitor the differential pressure across air filters273 via filter air pressure sensor 280. In some embodiments, if thedifferential pressure drops across air filters 273 by more than apredetermined amount (e.g. 0.75 IWG), controller 227 can send a dirtyfilter alarm.

FIG. 3 depicts a side view of data module 110 a. A discussed above, airmodules 105 can provide supply air to sub-floor space 120 a,pressurizing sub-floor space 120 a.

Damper Operation

In some embodiments, data module 110 a includes controller 305.Controller 305 can open return air damper 310 when data module 110 a isin use (e.g., when data module 110 a contains running IT equipment 315).Controller 305 can monitor the position of return air damper 310 andreport an alarm condition if it deviates from the position the positioninstructed by controller 305. Return air damper 310 can permit air to beexhausted from data module 110 a into the surrounding environment.

In some embodiments, data module 110 a can include temperature andhumidity sensors 320 a and 320 b. In some embodiments, temperature andhumidity sensors 320 a can be in cold aisle 325. Temperature andhumidity sensors 320 b can be in hot aisle 330. Separator 340 canfacilitate separating cold aisle 325 and hot aisle 330. In someembodiments, zones can be formed in cold aisle 325 or hot aisle 330. Forexample, a first half of cold aisle 325 can be designated as Zone A andinclude first temperature and humidity sensors 320 a and a second halfof cold aisle 325 can be designated as Zone B and include secondtemperature and humidity sensors 320 a. Hot aisle 330 can includesimilar zones and temperature and humidity sensor placement. Controller305 can modulate supply air damper 335 in zone A to maintain a hot aisletemperature of a predetermined hot aisle temperature setpoint (e.g.,100° F.) in Zone A. Controller 305 can modulate supply air damper 335 inZone B to maintain a hot aisle temperature of a predetermined hot aisletemperature setpoint (e.g., 100° F.) in Zone B. In some embodiments, ifthe hot aisle temperature in Zone A or Zone B cannot be maintained at orbelow a predetermined hot aisle temperature setpoint (e.g., 100° F.)after fully opening supply air damper 335, controller 305 can report acooling failure alarm.

In some embodiments, controller 305 can monitor the position of supplyair damper 335 and report an alarm condition if it deviates from theposition instructed by controller 305.

In some embodiments, if controller 305 fails, return air damper 310 andsupply air damper 335 can fail in the last instructed position.

In some embodiments, controller 305 can monitor the cold aisle 335temperature and humidity. If the temperature rises above a predeterminedcold aisle maximum temperature setpoint (e.g., 78° F.), controller 305can override the supply damper modulation and control it to bring thecold aisle 335 temperature to a predetermined cold aisle temperature setpoint (e.g., 75° F.). If the temperature remains above the predeterminedcold aisle maximum temperature setpoint (e.g., 78° F.), controller 305can report an alarm. In some embodiments, if the dew point temperaturein cold aisle 325 or hot aisle 330 is above a maximum dew point setpoint(e.g., 59° F.) or below a minimum dew point temperature set point (e.g.,42° F.), controller 305 can report an alarm.

In some embodiments, if smoke is detected within data module 110 a,controller 305 can report an alarm. Controller 110 a can fully closereturn air damper 310 and supply air damper 335 before a clean agent isreleased from fire suppression tanks.

FIG. 4 depicts a side view of data module 400. Data module 400 can beconnected to an air module as described above with data modules 110. Forexample, data module 400 can receive supply air via sub-floor space 405.Controller 410 can modulate supply air dampers 415 and return airdampers 420 based on temperature and humidity sensors 425 as describedabove with respect to data module 110 a.

FIG. 5 depicts an exemplary air flow through data module 500. Supply aircan be provided to sub-floor space 505 through air intake opening 510.Air intake opening 510 can be connected to, for example, supply airconduit 115 of FIG. 1A or another data module. A portion of supply aircan flow out of subfloor space 505 through exit opening 515. Exitopening 515 can connect to the sub-floor space of another data module,thereby providing supply air to the data module. In some embodiments,data module 500 can be the last data module in the series of datamodules receiving supply air from one or more particular air modules,and can have a closing plate in place of exit opening 515.

As described above, sub-floor space 505 can be pressurized by one ormore air modules. A portion of the supply air can flow through supplyair damper 520 into cold aisle 525 as a result of a pressuredifferential between sub-floor space 505 and cold aisle 525. Air canflow through IT equipment 530, removing heat from IT equipment 530, andinto hot aisle 535. Air from hot aisle 535 can be exhausted throughreturn damper 540.

FIG. 6 depicts a data center 600. Data center 600 is a data centerconfiguration in which the technology described herein can be utilized.Data center 600 includes air modules 605 a-605 d (generally air modules605). Air modules 605 are connected to data modules 610 a-610 e viasupply air conduit 615 and return air conduit 620. Supply air conduit615 and return air conduit 620 can be pipes, ducts, or any other conduitfor carrying air between air modules 605 and data modules 610. Airmodules 605 can provide supply air to data modules 610 via supplyconduit 615. Return air can be carried from data modules 610 to airmodules 605 via return air conduit 620. In some embodiments, air modules605 pressurize the supply air in supply air conduit 615, creatingpressure differential between the air pressure in the supply air conduit615 and the return air conduit 620. The pressure differential can causeair (e.g., supply air) to flow from air modules 605 to data modules 610,air to flow through data modules 610, and air (e.g., return air) to flowfrom data modules 610 to air modules 605. In some embodiments, airmodules 605 and data modules 610 can operate as described above.

Method steps can be performed by one or more programmable processorsexecuting a computer program to perform functions of the technology byoperating on input data and generating output. Method steps can also beperformed by, and apparatus can be implemented as, special purpose logiccircuitry, e.g., an FPGA (field programmable gate array) or an ASIC(application-specific integrated circuit). Modules can refer to portionsof the computer program and/or the processor/special circuitry thatimplements that functionality.

Processors suitable for the execution of a computer program include, byway of example, both general and special purpose microprocessors, andany one or more processors of any kind of digital computer. Generally, aprocessor receives instructions and data from a read-only memory or arandom access memory or both. The essential elements of a computer are aprocessor for executing instructions and one or more memory devices forstoring instructions and data. Generally, a computer also includes, orbe operatively coupled to receive data from or transfer data to, orboth, one or more mass storage devices for storing data, e.g., magnetic,magneto-optical disks, or optical disks. Data transmission andinstructions can also occur over a communications network. Informationcarriers suitable for embodying computer program instructions and datainclude all forms of non-volatile memory, including by way of examplesemiconductor memory devices, e.g., EPROM, EEPROM, and flash memorydevices; magnetic disks, e.g., internal hard disks or removable disks;magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor andthe memory can be supplemented by, or incorporated in special purposelogic circuitry.

The technology has been described in terms of particular embodiments.The alternatives described herein are examples for illustration only andnot to limit the alternatives in any way. The steps of the technologycan be performed in a different order and still achieve desirableresults.

What is claimed is:
 1. An air module comprising: a controller; an airintake module configured to receive first air from a first air sourceand to receive second air from a second air source; an evaporativecooling module in fluid communication with the air intake module; amechanical cooling module in fluid communication with the evaporativecooling module; and wherein the controller is configured to: cause theintake module to mix, based on at least a supply air temperature setpoint, the first air and the second air to form intake air, andselectively cool the intake air to form supply air by at least one ofcausing the evaporative cooling module to selectively cool, based on atleast the supply air temperature set point, the intake air, and causingthe mechanical cooling module to selectively cool the intake air basedon at least the supply air temperature set point.
 2. The air module ofclaim 1, wherein the first air source is a source of return air, andwherein the second air source is a source of outside air.
 3. The airmodule of claim 1, wherein the controller is further configured to: formthe supply air substantially from the first air, if: a temperature ofthe first air is less than the supply air temperature set point.
 4. Theair module of claim 1, wherein the controller is further configured to:form the supply air by mixing the first air and the second air, if: afirst temperature of the first air is greater than the supply airtemperature set point, a second temperature of the second air is lessthan or equal to the supply air temperature set point, and a dew pointof the second air is less than or equal to an upper limit of a dew pointrange and greater than or equal to a lower limit of the dew point range.5. The air module of claim 1, wherein the controller is furtherconfigured to: form mixed air by mixing the first air and the secondair, if: a first temperature of the first air is greater than the supplyair temperature set point, a second temperature of the second air isless than the first temperature, a dew point of the second air is lessthan a lower limit of a dew point range, and a wet bulb temperature ofthe second air is less than or equal to a wet bulb temperaturecorresponding to the supply air temperature set point at the lower limitof a dew point range; and form the supply air by evaporatively coolingmixed air with the evaporative cooling module.
 6. The air module ofclaim 1, wherein the controller is further configured to: form supplyair substantially from the second air by evaporatively cooling thesecond air with the evaporative cooling module, if: a first temperatureof the first air is greater than the supply air temperature set point, asecond temperature of the second air is greater than the supply airtemperature set point, a dew point of the second air is less than orequal to an upper limit of a dew point range, and a wet bulb temperatureof the second air is within an evaporative cooling wet bulb temperaturerange.
 7. The air module of claim 1, wherein the controller is furtherconfigured to: form supply air substantially from the first air bymechanically cooling the first air with the mechanical cooling module,if: a dew point of the second air is greater than an upper limit of adew point range, a dew point of the first air is less than or equal toan upper limit of a dew point range, and a first temperature of thefirst air is greater than the supply air temperature set point; and formsupply air substantially from the first air by mechanically cooling thefirst air with the mechanical cooling module, if: a wet bulb temperatureof the second air is greater than or equal to an upper limit of anevaporative cooling wet bulb temperature range, a dew point of the firstair is less than or equal to an upper limit of a dew point range, and afirst temperature of the first air is greater than the supply airtemperature set point.
 8. The air module of claim 1, wherein thecontroller is further configured to: form supply air substantially fromthe first air by mechanically cooling the first air with the mechanicalcooling module, if: a dew point of the first air is greater than anupper limit of a dew point range, and a dew point of the second air isgreater than the upper limit of a dew point range; and form supply airsubstantially from the first air by mechanically cooling the first airwith the mechanical cooling module, if: a dew point of the first air isgreater than an upper limit of a dew point range, and a wet bulbtemperature of the second air is greater than or equal to an upper limitof an evaporative cooling wet bulb temperature range.
 9. The air moduleof claim 1, wherein the controller is further configured to: form supplyair substantially from the second air by evaporatively cooling thesecond air with the evaporative cooling module, if: a dew point of thefirst air is less than a lower limit of a dew point range; a dew pointof the second air is less than the lower limit of the dew point range; afirst temperature of the first air is greater than the supply airtemperature set point; a second temperature of the second air is greaterthan the first temperature of the first air; and a wet bulb temperatureof the second air is less than a wet bulb temperature corresponding tothe supply air temperature set point at the lower limit of the dew pointrange.
 10. The air module of claim 1, wherein the controller is furtherconfigured to: form mixed air by mixing the first air at a firsttemperature and the second air at a second temperature, if: the secondtemperature of the second air is greater than the first temperature ofthe first air; a dew point of the first air is greater than a lowerlimit of a dew point range; and a dew point of the second air is lessthan the lower limit the dew point range; and form the supply air byevaporatively cooling the mixed air with the evaporative cooling module.11. A computer implemented method for controlling an air modulecomprising: generating, by a controller, a first instruction to cause anintake module to selectively mix, based upon a supply air temperatureset point, first air and second air to form intake air; generating, bythe controller, a second instruction to selectively cool the intake airto form supply air, wherein the second instruction comprises at leastone of instructions to cause an evaporative cooling module toselectively cool, based on at least the supply air temperature setpoint, the intake air, and instructions to cause a mechanical coolingmodule to selectively cool, based on at least the supply air temperatureset point, the intake air; and operating the air module according thefirst and second instructions.
 12. The method of claim 11, wherein thefirst instruction comprises instructions to form the intake airsubstantially from the first air, if: a temperature of the first air isless than the supply air temperature set point.
 13. The method of claim11, wherein the first instruction comprises instructions to form theintake air by mixing the first air and the second air, if: a firsttemperature of the first air is greater than the supply air temperatureset point, a second temperature of the second air is less than or equalto the supply air temperature set point, and a dew point of the secondair is less than or equal to an upper limit of a dew point range andgreater than or equal to a lower limit of the dew point range.
 14. Themethod of claim 11, wherein the first instruction comprises instructionsto form intake air by mixing the first air and the second air and thesecond instruction comprises instructions to cause the evaporativecooling module to selectively cool, based on at least the supply airtemperature set point, the intake air, if: a first temperature of thefirst air is greater than the supply air temperature set point, a secondtemperature of the second air is less than the first temperature, a dewpoint of the second air is less than a lower limit of a dew point range,and a wet bulb temperature of the second air is less than or equal to awet bulb temperature corresponding to the supply air temperature setpoint at the lower limit of a dew point range.
 15. The method of claim11, wherein the first instruction comprises instructions to createintake air substantially from second air and the second instructioncomprises instructions to cause the evaporative cooling module toselectively cool, based on at least the supply air temperature setpoint, the intake air, if: a first temperature of the first air isgreater than the supply air temperature set point, a second temperatureof the second air is greater than the supply air temperature set point,a dew point of the second air is less than or equal to an upper limit ofa dew point range, and a wet bulb temperature of the second air iswithin an evaporative cooling wet bulb temperature range.
 16. The methodof claim 11, wherein the first instruction comprises instructions tocreate intake air substantially from first air, wherein the secondinstruction comprises instructions to cause the mechanical coolingmodule to selectively cool, based on at least the supply air temperatureset point, the intake air, if: a dew point of the second air is greaterthan an upper limit of a dew point range, a dew point of the first airis less than or equal to an upper limit of a dew point range, and afirst temperature of the first air is greater than the supply airtemperature set point; and wherein the first instruction comprisesinstructions to create intake air substantially from first air and thesecond instruction comprises instructions to cause the mechanicalcooling module to selectively cool, based on at least the supply airtemperature set point, the intake air, if: a wet bulb temperature of thesecond air is greater than or equal to an upper limit of an evaporativecooling wet bulb temperature range, a dew point of the first air is lessthan or equal to an upper limit of a dew point range, and a firsttemperature of the first air is greater than the supply air temperatureset point.
 17. The method of claim 11, wherein the first instructioncomprises instructions to create intake air substantially from first airand the second instruction comprises instructions to cause themechanical cooling module to selectively cool, based on at least thesupply air temperature set point, the intake air, if: a dew point of thefirst air is greater than an upper limit of a dew point range, and a dewpoint of the second air is greater than the upper limit of a dew pointrange; and wherein the first instruction comprises instructions tocreate intake air substantially from first air and the secondinstruction comprises instructions to cause the mechanical coolingmodule to selectively cool, based on at least the supply air temperatureset point, the intake air, if: a dew point of the first air is greaterthan an upper limit of a dew point range, and a wet bulb temperature ofthe second air is greater than or equal to an upper limit of anevaporative cooling wet bulb temperature range.
 18. The method of claim11, further comprising: wherein the first instruction comprisesinstructions to create intake air substantially from second air and thesecond instruction comprises instructions to cause the evaporativecooling module to selectively cool, based on at least the supply airtemperature set point, the intake air, if: a dew point of the first airis less than a lower limit of a dew point range; a dew point of thesecond air is less than the lower limit of the dew point range; a firsttemperature of the first air is greater than the supply air temperatureset point; a second temperature of the second air is greater than thefirst temperature of the first air; and a wet bulb temperature of thesecond air is less than a wet bulb temperature corresponding to thesupply air temperature set point at the lower limit of the dew pointrange.
 19. The method of claim 11, further comprising: wherein the firstinstruction comprises instructions to form intake air by mixing thefirst air at a first temperature and the second air at a secondtemperature, and the second instruction comprises instructions to causethe evaporative cooling module to selectively cool, based on the atleast the supply air temperature set point, the intake air, if: thesecond temperature of the second air is greater than the firsttemperature of the first air; a dew point of the first air is greaterthan a lower limit of a dew point range; and a dew point of the secondair is less than the lower limit the dew point range.
 20. A modular datacenter comprising: an air module comprising: an air module controller;an air intake module configured to receive first air from a first airsource and to receive second air from a second air source; anevaporative cooling module in fluid communication with the air intakemodule; a mechanical cooling module in fluid communication with theevaporative cooling module; a fan array in fluid communication with themechanical cooling module; wherein the air module controller isconfigured to cause the intake module to mix the first air and thesecond air based on at least a supply air temperature set point to formintake air, and wherein the controller is configured to form supply airby at least one of causing the evaporative cooling module to cool theintake air selectively based on at least the supply air temperature setpoint, and causing the mechanical cooling module to cool the intake airselectively based on at least the supply air temperature set point; oneor more data center modules comprising a data center module controller;a data center module intake damper configured to control supply airentering the data center module; wherein the data center modulecontroller is configured to actuate the data center module intake damperbased on at least one of a temperature and humidity of air in the datacenter module; and a supply air conduit in fluid communication with theair module and a data center module via the data center module intakedamper of the one or more data center modules to carry supply air fromthe air module to the one or more data center modules, wherein the airmodule controller is further configured to adjust an air flow of the fanarray to maintain a substantially constant air pressure in the supplyair conduit.